Particle model

Which diagram shows the change in the arrangement of the molecules in a solid as the substance melts?

May/June 2015

A quantity of gas is enclosed in a sealed container. The gas is cooled while the container’s volume remains unchanged. What occurs to the gas molecules?

May/June 2015

A gas in a container with constant volume is heated. What happens to the gas molecules?

May/June 2016

When a sample of a solid is heated, it melts into a liquid and then changes into a gas.

May/June 2017

A closed container of gas is warmed, causing the pressure inside to rise. What happens to the gas molecules that leads to this rise in pressure?

May/June 2018

As shown in Fig. 3.1, a passenger on an aircraft seals a plastic bag that contains air.

May/June 2018

The pressure of the gas in a sealed syringe is increased slowly until it becomes twice its original value. The gas volume falls to half its starting value. What has to be true about the gas’s density and temperature?

May/June 2019

In low-pressure hydrogen, the molecules experience no intermolecular forces apart from when they collide with one another. Which statement describes how a molecule moves between one collision and the next?

May/June 2019

A gas is contained in a vessel with a constant volume. Heat energy is transferred to the gas from an outside source. What occurs to the gas molecules?

May/June 2019

Fig. 4.1 shows a cylinder fitted with a piston and containing a gas.

May/June 2019

Air in a sealed container with a fixed volume is heated up. The air pressure rises. In what way do the air molecules produce this rise in pressure?

May/June 2021

Which row states the particle arrangement and the forces between particles in a solid?

May/June 2022

A fixed mass of gas occupies a volume $V_1$ at an initial pressure of $p_1$. It then expands while the temperature stays constant until its volume becomes $V_2$ and its pressure is $p_2$. Which statement about the gas pressure and volume is incorrect?

May/June 2022

Which row compares, for a solid and a liquid, the forces between the particles and the distances between the particles?

May/June 2023

In one experiment, the volume of a gas in a cylinder is recorded while the gas pressure is increased. The readings obtained are listed below. Pressure $P/\text{Pa}$: $1.0\times10^5$, $2.0\times10^5$, $3.0\times10^5$, $4.0\times10^5$ Volume $V/\text{m}^3$: $20\times10^{-5}$, $10\times10^{-5}$, $6.0\times10^{-5}$, $4.0\times10^{-5}$ Suggest a possible explanation for these results?

May/June 2023

A fixed mass of gas is enclosed in a glass tube by a seal at one end and a mercury column. The mercury can move freely along the tube. The tube is turned slowly from the vertical in Fig. 3.1 to the horizontal in Fig. 3.2. As this happens, the gas volume increases while its temperature stays constant.

May/June 2023

A gas undergoes slow expansion while its temperature stays unchanged. What happens to the particles of the gas?

May/June 2024

Air in each of four syringes is compressed slowly, keeping the air temperature constant. The table shows the volume of the air before and after compression for each syringe. At the start, the air in all four syringes is at the same pressure. Which syringe has the smallest change in pressure?

May/June 2024

A clear box has a partition wall at its centre. Each side contains a different gas, as shown. The partition is taken away. The box is then left undisturbed for a long time. The gases do not undergo any reaction. What is observed in the box after this?

May/June 2024

Air is heated in a closed container whose volume stays constant. Why does the air pressure rise as the temperature rises?

May/June 2025

A fixed mass of air occupies a volume of $150\ \text{cm}^3$ and is at a pressure of $120\ \text{kPa}$. The volume of the air is then altered to $100\ \text{cm}^3$. The temperature of the air stays constant. What is the air’s new pressure?

May/June 2025

A gas is confined in a cylinder by a piston that can move. The gas column has a length of $20\,\text{cm}$ and the pressure in the cylinder is $p$. The piston is drawn out by $30\,\text{cm}$, making the gas column $50\,\text{cm}$ long. The temperature of the gas remains unchanged. What is the gas’s new pressure?

Oct/Nov 2015

A gas is enclosed in a sealed container whose volume stays constant. When the gas is heated, the pressure exerted by the gas on the container walls increases. How do the gas particles produce this rise in pressure?

Oct/Nov 2015

A gas is enclosed in a cylinder by a piston while under atmospheric pressure. A movable rod keeps the piston in a fixed position. Figure 6.1 shows the cylinder. The cylinder is heated. As the gas temperature rises, the pressure rises as well.

Oct/Nov 2015

Which statement explains the way in which a gas exerts pressure on a container?

Oct/Nov 2016

A gas undergoes a slow expansion while its temperature stays unchanged. What occurs to the gas molecules?

Oct/Nov 2016

Gas is contained in a syringe by a piston, while the narrow end of the syringe is sealed, as illustrated in Fig. 5.1. When the gas is at a pressure of $1.1 \times 10^{5}\,\text{Pa}$, it has a volume of $40\,\text{cm}^3$.

Oct/Nov 2016

A gas is warmed in a sealed container at fixed volume. What occurs to the molecules of the gas?

Oct/Nov 2017

A liquid needs an extremely large rise in pressure to be compressed, whereas a gas can be compressed with a much smaller rise in pressure. Which statement explains this?

Oct/Nov 2017

A piston traps air inside a cylinder. The air pressure is $p$ and the air column has a length of $20\ \text{cm}$. The piston is then pulled outwards until the air column is $40\ \text{cm}$ longer than before. The temperature of the air stays constant. What is the air pressure now?

Oct/Nov 2018

A gas is enclosed in a sealed container. The gas is then cooled while the container volume remains unchanged. What happens to the gas molecules?

Oct/Nov 2018

A piston traps air in a cylinder. The air has pressure $p$, and the air column measures $20\,\text{cm}$ in length. The piston is drawn outwards until the length of the air column has increased by $40\,\text{cm}$. The temperature of the air stays constant. What is the new air pressure?

Oct/Nov 2018

A gas is enclosed in a sealed container. The gas is cooled while the container’s volume is held constant. What happens to the gas molecules?

Oct/Nov 2018

Which graph represents the link between pressure and volume for a fixed mass of gas at constant temperature?

Oct/Nov 2019

A smoke particle Z is observed to move in a random manner while suspended in air, as shown. Which statement best explains the random movement of Z?

Oct/Nov 2020

A gas enclosed in a cylinder is compressed by a piston while the temperature is kept constant. Which property of the gas stays the same?

Oct/Nov 2020

The diagram represents a diver at a depth of $20\ \text{m}$ beneath the lake surface. At this depth, the total pressure is $3.0 \times 10^5\ \text{Pa}$. An air bubble has a volume of $0.60\ \text{cm}^3$ when it leaves the diver. It then travels up to the lake surface, where the pressure is $1.0 \times 10^5\ \text{Pa}$. The temperature of the air in the bubble stays constant. What is the volume of the air bubble at the surface of the lake?

Oct/Nov 2020

A quantity of gas is enclosed in a cylinder by a piston that can move. When the piston is pushed inward, the gas volume gets smaller while the temperature remains unchanged. What happens to the gas pressure, and what is the reason?

Oct/Nov 2020

A gas syringe holds a gas volume $V_1$ at pressure $p_1$. Its volume is decreased to $V_2$ with no change in temperature. What expression gives the change in pressure?

Oct/Nov 2022

A quantity of gas is enclosed in a large syringe. The atmospheric pressure is $100\,\text{kPa}$. The gas pressure is $200\,\text{kPa}$ above atmospheric pressure. As the piston moves outwards, the volume of the enclosed gas doubles. The temperature stays constant. What is the new gas pressure?

Oct/Nov 2023

A sealed cylinder that contains gas is placed in direct sunlight. After some time, the cylinder bursts. How can this be explained in terms of the motion and behaviour of the gas particles?

Oct/Nov 2023

A gas is enclosed in a cylinder by a movable piston. The gas column has a length of $20\,\text{cm}$ and the pressure in the cylinder is $p$. The piston is drawn out by $30\,\text{cm}$, making the gas column length $50\,\text{cm}$. The temperature of the gas remains unchanged. What is the gas pressure now?

Oct/Nov 2023

Air at atmospheric pressure and room temperature is confined in an insulated container by a frictionless piston of negligible weight. By putting masses on the top of the piston, the air can be compressed. A mass of $1.0\,\text{kg}$ is placed on the piston and the volume of the trapped air falls from $100\,\text{cm}^3$ to $90\,\text{cm}^3$. Which statement is correct?

Oct/Nov 2024

Air at a pressure of $1.0 \times 10^{5}\,\text{N m}^{-2}$ is held in a container by a piston. A force is used to push the piston downward into the container. The temperature of the air stays constant. The distance from the base of the container to the piston falls from $0.18\,\text{m}$ to $0.15\,\text{m}$. What is the new air pressure inside the container?

Oct/Nov 2024

A sealed gas syringe contains a gas maintained at constant volume. Which row shows how a change in the gas temperature affects its pressure?

Oct/Nov 2024

Fig. 3.1 shows gas at room temperature inside a metal cylinder. A metal piston is fixed in place so the gas is trapped. The metal cylinder is placed in boiling water, causing the trapped gas temperature to rise.

Oct/Nov 2024